doc(picker & date-picker): add version mark to keep-index

components/date-picker/README.en-US.md

@@ -31,7 +31,7 @@ Vue.component(DatePicker.name, DatePicker)
 |text-render|customized option for text displaying|Function(typeFormat, column0Value, column1Value, ...): String|-|`unit-text` is invalid when using `text-render`, refer to `Appendix`|              
 |today-text|displaying text of today|String|`today`|use `&` to take placeholder date, like `&(today)`| 
 |line-height|line height of options|Number|`45`|unit `px`| 
-|keep-index|keep last stop position when the column data changes|Boolean|`false`|-|          
+|keep-index <sup class="version-after">2.5.2+</sup>|keep last stop position when the column data changes|Boolean|`false`|-|          
 |is-view|inline-display in page, otherwise it shows as `Popup`|Boolean|`false`|-| 
 |title|title of date-picker|String|-|-|
 |describe|description of date-picker|String|-|-|

components/date-picker/README.md

@@ -31,7 +31,7 @@ Vue.component(DatePicker.name, DatePicker)
 |text-render|自定义选项展示文案方法|Function(typeFormat, column0Value, column1Value, ...): String|-|如果使用`text-render`则`unit-text`无效, 示例见附录|
 |today-text|今天展示文案设置|String|`今天`|使用`&`可占位日期数字，如`&(今天)`| 
 |line-height|选择器选项行高|Number|`45`|单位`px`|  
-|keep-index|当列数据变化时保持上次停留的位置|Boolean|`false`|-|        
+|keep-index <sup class="version-after">2.5.2+</sup>|当列数据变化时保持上次停留的位置|Boolean|`false`|-|        
 |is-view|是否内嵌在页面内展示, 否则以弹层形式|Boolean|`false`|-| 
 |title|选择器标题|String|-|-|
 |describe|选择器描述|String|-|-|

components/picker/README.en-US.md

@@ -29,7 +29,7 @@ Vue.component(Picker.name, Picker)
 |invalid-index|indexes of disabled items in each column|Array|`[]`|array of multiple disabled items, such as `[[1,2], 2]`|
 |is-view|inline display in page, otherwise it shows as `Popup`|Boolean|`false`|-|
 |is-cascade|data in each column is cascaded or not|Boolean|`false`|see #Appendix for the format of cascaded data|
-|keep-index|keep last stop position when the column data changes|Boolean|`false`|only for cascaded data|  
+|keep-index <sup class="version-after">2.5.2+</sup>|keep last stop position when the column data changes|Boolean|`false`|only for cascaded data|  
 |line-height|line height of options|Number|`45`|unit `px`|
 |title|title of picker|String|-|-|
 |describe|description of picker|String|-|-|

components/picker/README.md

@@ -30,7 +30,7 @@ Vue.component(Picker.name, Picker)
 |line-height|选择器选项行高|Number|`45`|单位`px`|
 |is-view|是否内嵌在页面内展示，否则以弹层形式|Boolean|`false`|-|
 |is-cascade|各列数据是否级联|Boolean|`false`|级联数据格式见附录|
-|keep-index|当列数据变化时保持上次停留的位置|Boolean|`false`|仅用于级联数据|  
+|keep-index <sup class="version-after">2.5.2+</sup>|当列数据变化时保持上次停留的位置|Boolean|`false`|仅用于级联数据|  
 |title|选择器标题|String|-|-|
 |describe|选择器描述|String|-|-|
 |ok-text|选择器确认文案|String|`确认`|-|